DriPP: Driven Point Processes to Model Stimuli Induced Patterns in M/EEG Signals

TL;DR

This paper introduces DriPP, a novel driven point process model for analyzing EEG/MEG signals, enabling the detection of stimulus-related neural patterns and their modulation by cognitive tasks.

Contribution

The paper develops a new statistical driven temporal point process model and an efficient EM algorithm for analyzing stimulus-induced patterns in EEG/MEG data.

Findings

Successfully identifies event-related neural responses.

Isolates non-task specific temporal patterns.

Demonstrates effectiveness on standard MEG datasets.

Abstract

The quantitative analysis of non-invasive electrophysiology signals from electroencephalography (EEG) and magnetoencephalography (MEG) boils down to the identification of temporal patterns such as evoked responses, transient bursts of neural oscillations but also blinks or heartbeats for data cleaning. Several works have shown that these patterns can be extracted efficiently in an unsupervised way, e.g., using Convolutional Dictionary Learning. This leads to an event-based description of the data. Given these events, a natural question is to estimate how their occurrences are modulated by certain cognitive tasks and experimental manipulations. To address it, we propose a point process approach. While point processes have been used in neuroscience in the past, in particular for single cell recordings (spike trains), techniques such as Convolutional Dictionary Learning make them amenable to human studies based on EEG/MEG signals. We develop a novel statistical point process model-called driven temporal point processes (DriPP)-where the intensity function of the point process model is linked to a set of point processes corresponding to stimulation events. We derive a fast and principled expectation-maximization (EM) algorithm to estimate the parameters of this model. Simulations reveal that model parameters can be identified from long enough signals. Results on standard MEG datasets demonstrate that our methodology reveals event-related neural responses-both evoked and induced-and isolates non-task specific temporal patterns.